Process for the production of the carbon chloride compounds c4cl6



Patented Jan. 19, 1943 PROCESS FOR THE PRODUCTION OF THE CARBON CHLORIDECOMPOUNDS C4CL6 Josef Wimmer, Muckenberg, District of lichenwerda,Germany; vested in the Allen Property Custodian No Drawing. ApplicationMay is, 1940, Serial No. 336,005. In Germany June a, 1939 5 Claims.

The invention relates to a process for the production of thecarbon-chloride compound C4C1s as set forth in Mugdan and Wimmer ap-.chloride catalysts, especially ferric chloride and antimony chloride,be caused to split 01f two mols of HCl and absorb one mol of chlorine,to produce a new compound of the formula C4016. The steps, that is, thesplitting off of each mol of HCl and the addition of the chlorine, maybe carried out in any desired order.

I have now found that in .the place of dimeric trichlorethylene asstarting material in the process described above, it is possible to usechlorinated hydrocarbons such as occur in waste products of chemicalprocesses and distillations, especially in the distillation residues oftechnical tetrachlorethane and trichlorethylene. The chief constituentsof these residues, in addition to hexachlorethane are1.1.2.3.4A-hexachlbrbutane and 1.2.3.4-tetrachlorbutadien, and otherchlorinated hydrocarbons which are formed from these materials duringthe production of tetrachlorethaneand trichlorethylene. The method ofworking according to the above application S. N. 199,290 can be appliedwithout difiiculty to these mixtures of chlorinated hydrocarbons, itbeing desirable first to free them of the lowest and highest boilingconstituents. The end point of the reaction can be recognized by thefact that the reaction liquid neither absorbs any further chlorine norsplits 011 any further 1101.

Example-From the above mentioned technical trichlorethylene residuefirstly the low boilin C2 chlorinated hydrocarbons, especiallytetrachlorethylene, were fractioned ofl'. Then the constituent of thehighest boiling fraction which could be distilled, was distilled over atreduced pressure. From kg. of the starting material 7-9 kg. of thispurified residue were obtained according to the conditions under whichthe residue of distillation was obtained. 3 kg. 01' this residue weremixed with 3 g. of ferric chloride and treated with chlorine at IO-80 C.After having completed the absorption of chlorine, the temperature wasgradually increased to about 170 C. The splitting of! of HCl began at100 C. and was very active at 140 C. When the splitting ofl of H01 hadnearly ceased the reaction product was treated with chlorine again andheated for the splitting 03 01 HCl. The end of this reaction processcould be recognized by the fact that the reaction liquid neitherabsorbed any further chlorine, nor split off HCl. The end product. thencontained: 2.7 kg. C4Cle and 0.8 kg. hexachlorethane. Thehexachlorethane was partly present in the starting material, partly 1twas formed at the chlorination by the decomposition of the C4-- chain.

From mixture of the hexachlorbutadien' and hexachlorethane firstobtained the hexachlorethane can be entirely separated, under suitableconditions.

If necessary one'part of the hexachlorethane can be eliminated byfreezing out, but it is also possible to iractionate all thehexachlorethane directly. The difliculty in this procedure is that thehexachlorethane crystallizes out in the condenser and tendsto clog thecondenser. Therefore it is preferable toproceed in this way: The vapoursof the hexachlorethane are not condensed by cooling down from theoutside but by a direct injection of cold water into the condensationtube which is employed for this purpose. It is also possible to mix thecrude product with a liquid having nearly the same boiling point as thehexachlorethane and the property of dissolving the hexachlorethanesatisfactorily. In this way too a choking of the condenser is avoided.It is possible to use as an auxiliary liquid for this purpose the lowestboiling constituent of the trichlorethylene residue which is freed fromethane derivatives.

In this manner or by similar measures, the hexachlorbutadien product caneasily be prepared in a pure state.

If the reaction temperatures are sufiiciently high, the chlorination andthe splitting off of 1301 can be carried out at the same time. It isalso possible to begin with a splitting off of HCl and then continuewith'the chlorination. Other variations are also possible. Preferably,

j when residues of tetrachlorethane are treated,

the first step is a splitting ofi of HCl.

The residues of trichlorethylene and tetrachlorethane have been auseless waste product containing chlorinated hydrocarbons with 4 carbonatoms in a straight chain with chlorine in the presence of ferricchloride as a catalyst to cause both the splitting-oil of RC1 and theaddition of chlorine, till no more 1101 is split off and no morechlorine is added.

2. Process for producing a carbon-chloride of the formula C 4C1s whichcomprises heating distillation residues of technical tetrachloroethanefrom which the lowest and highest boiling components have been distilledoil, and which contain chlorinated hydrocarbons with four carbon atomsin a straightchain, with chlorine in the presence of ferric chloride asa catalyst to cause both the splitting-oi! of HCl and the addition ofchlorine till no more HCl is split oi! and no more chlorine is added.- a

3. Process for producing a carbon-chloride of the formula C4Clu whichcomprises heating distillation residues of technical trichlorethylenefrom which the lowest and highest boiling components have been distilledofi, and which contain chlorinated hydrocarbons with four carbon atomsin a straight chain, with chlorine in the presence of ferric chloride asa catalyst to cause both the splitting-oi! of HCl and the addition ofchlorine till no more HCl is split of! and no more chlorine is added.

2,aoe,'oos V 4. Process for producing a carbon-chloride of the formulaC4Cla which comprises heating waste products of chemical processes anddistillations containing chlorinated hydrocarbons with 4 carbon atoms ina straight chain with chlorine in the presence of ferric chloride as acatalyst to cause both the splitting-on of HCl and the addition ofchlorine till no more 1101 is split 01! and no more chlorine is added,and fractionating the obtained mixture of the carbon-chloride C461; andhexachlorethane in the presence of 'a solvent for hexachlorethane havinga boiling point near to the boiling point of hexachlorethane.

5. Process for producing a carbon-chloride of the formula C4010 whichcomprises heating waste products of chemical processes and distillationscontaining chlorinated hydrocarbons with .4 carbon atoms in a straightchain with chlorine in the presence of ferric chloride as a catalyst tocause both the splitting-oi! of H01 andthe addition of chlorine till nomore HCl is split 01! and no more chlorine is added, and fractionatingthe obtained mixture of the carbon-chloride C4011 and. hexachlorethanein a tube while spraying water on the inner wall of'the tube.

JOSEF

